Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271139AbTGQLb6 (ORCPT ); Thu, 17 Jul 2003 07:31:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271184AbTGQLb6 (ORCPT ); Thu, 17 Jul 2003 07:31:58 -0400 Received: from kweetal.tue.nl ([131.155.3.6]:1284 "EHLO kweetal.tue.nl") by vger.kernel.org with ESMTP id S271139AbTGQLb5 (ORCPT ); Thu, 17 Jul 2003 07:31:57 -0400 Date: Thu, 17 Jul 2003 13:46:47 +0200 From: Andries Brouwer To: Andrew Morton Cc: Joel Becker , zippel@linux-m68k.org, aebr@win.tue.nl, greg@kroah.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] print_dev_t for 2.6.0-test1-mm Message-ID: <20030717134647.A2347@pclin040.win.tue.nl> References: <20030716213451.GA1964@win.tue.nl> <20030716143902.4b26be70.akpm@osdl.org> <20030716222015.GB1964@win.tue.nl> <20030716152143.6ab7d7d3.akpm@osdl.org> <20030717014410.A2026@pclin040.win.tue.nl> <20030716164917.2a7a46f4.akpm@osdl.org> <20030717082716.GA19891@ca-server1.us.oracle.com> <20030717091515.GC19891@ca-server1.us.oracle.com> <20030717022444.19c204ef.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20030717022444.19c204ef.akpm@osdl.org>; from akpm@osdl.org on Thu, Jul 17, 2003 at 02:24:44AM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1279 Lines: 28 On Thu, Jul 17, 2003 at 02:24:44AM -0700, Andrew Morton wrote: > And surely the task of mangling whatever comes off the wire into a dev_t for > init_special_inode() should be private to the Linux NFS client? > > Still wondering why we need to support a 16:16 encoding in [k]dev_t. I think I answered this already in earlier posts today. Again: (i) We need support for 16/32/64-bit dev_t. (ii) User space (glibc) has 64-bit dev_t. (iii) The split into major/minor is hardwired in , independent of filesystem. Thus, we must define major(),minor(),makedev(). (iv) For Linux the device number is a cookie - major and minor do not really have a significance - we just select a driver given a *dev_t interval. That means that there are no reasons for inventing more complicated setups like 12:20. And since you add "[k]": a kdev_t is internal to the kernel, we do whatever we want. I wanted a pointer (say, to a struct gendisk or so), but these days it seems we are heading for an arithmetic type, with 32:32. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/